Mobile concrete mixing and delivery system

ABSTRACT

There is disclosed a mobile apparatus for mixing and dispensing mixtures from an ingredients container including a hopper with a channel-shaped floor portion containing a screw auger. A cover over the screw auger may be raised so that a gap between the cover and the hopper walls allows metered amounts of ingredients to be conveyed by the screw auger to a separate mixer and a dispenser. The mixer and dispenser can be in the form of a tapering ribbon-blade mixer located in a frusto conical hollow body pivotally, slidably and extendably mounted at the rear of a transport vehicle. The mixer and dispenser can be pivotally mounted to a bracket mounted on rails to move slidably across the width of the transport vehicle.

FIELD OF THE INVENTION

This invention is concerned with a mobile batching and mixing apparatusfor mixtures of ingredients such as concrete, cement mortars, road basematerials, asphaltic road surfacing compounds, animal feedstuffs and thelike and also for transportation of particulate materials.

BACKGROUND OF THE INVENTION

The use of mobile batching apparatus and mobile mixing apparatus forconcrete mixtures in particular is well known as is the use of mobileapparatus which have combined batching and mixing functions.

The most commonly employed apparatus for mixing and transportation ofpre-mixed concrete and the like comprises a vehicle mounted agitatorbowl which receives the ingredients for a concrete mix from a stationarybatching plant and, by rotation of the agitator bowl, mixes the concretemixture prior to and during transit to a discharge site.

Whilst generally effective for their intended purpose, there are anumber of disadvantages associated with such mobile agitator bowlmixers. Only a relatively short time is available from the commencementof mixing to on site placement and as the use of chemical retardants canaffect concrete quality, generally such use is restricted. This shortmixing time thus limits the effective travelling radius of an agitatorbowl mixer to a distance which safely can be travelled during themaximum mixing time of the concrete batch. This can be a particularproblem in urban areas where a risk of transit delays due to trafficproblems is a likelihood. Moreover, if the mobile transit mixer isinvolved in a traffic accident or otherwise suffers a mechanicalbreakdown, the entire batch of concrete can be lost and if this isallowed to set in the agitator bowl, this necessitates replacement ofthe bowl.

Accordingly it is necessary to locate a plurality of stationary batchingplants at spaced locations in urban and suburban areas in order toprovide effective delivery radii for pre-mixed concrete. Apart frombeing inefficient in terms of double handling of raw materials, thisgives rise to substantial capital overheads and local inconvenience ofincreased vehicular traffic, dust and noise in the vicinity of batchingplants.

As cities grow, town planning and environmental constraints will limitor even reduce the number of batch plants permitted in an urbanenvironment. Already, town planning controls have placed restrictions onthe location, days of operation and hours of operation. With growingconstraints and competition in the industry, economic considerationshave driven organisations towards larger batch plants and transit mixerswith necessarily high capital investments and greater operationaloverheads.

With operational accuracies of larger batch plants more suited to largertransit mix batches, smaller capacity transit mixers are not wellserved. More importantly however, the capacity to serve a market forsmall to very small batches of premixed concrete has virtually beeneliminated.

Generally speaking, the carrying capacity of larger agitator bowl mixersis usually maximised to carry a pre-mixed batch of about 6.4 cubicmeters of concrete.

Where lesser quantities of concrete may be required, smaller agitatorbowl mixers may be employed to deliver batches of, say, 0.40 to 2.2cubic meters.

The main disadvantages of mobile agitator bowl mixers however is that inpractice, they should discharge their entire load once on site and thismust occur during a relatively short period of time. This can be grosslyinconvenient to users of concrete mixes who require less than thepredetermined mixer batch size and/or require discharge of smallquantities of concrete over a prolonged period of time.

In the supply of ready mixed concrete to a site, it is customary toorder an excess of about 10% over that calculated as required by theuser as the cost and inconvenience of undersupply or undercalculation istoo great. For example, if the quantity required is undersupplied by,say, 0.25 cubic meters, an extra delivery will be required. This cantake up to one hour for delivery while a concrete finishing crew is noteffectively employed, but as the minimum quantity supplied is normally0.4 cubic meters this gives rise to wastage. Moreover there exists therisk of a "cold joint" formation in the pour if there is a shortfall indelivery or a delay in delivery of a subsequent batch.

As there are now penalties for disposal of excess concrete dumped onsite, it is customary to add a retardant composition to any excessconcrete in the agitator bowl and return the excess to the batchingplant where it is dumped into a settling pond for separation andtreatment of water and recovery of aggregate and cement fines forreworking. Environmental controls associated with re-treatment of unusedconcrete add substantially to capital costs of a batching plant.

Other problems associated with conventional agitator bowl deliveryvehicles is that when rain is forecast or a delivery site is wet orboggy, such vehicles are not permitted on site due to the risk ofbecoming bogged and all of the attendant problems that arise therefromand transit mixers cannot be held on stand-by on site.

In order to overcome the disadvantages associated with conventionalagitator bowl mixers, there have been many proposals for mobile batchingand mixing apparatus employing bulk containers for sand, aggregate,cement powder, water etc, metering devices for each constituent and amixing and/or dispensing mechanism.

Australian Patent Application No. 27574/88 describes a mobilebatching/mixing apparatus comprising a plurality of hoppers, each with arespective metering means for discharging dry ingredients onto aconveyor belt located below the hoppers. The conveyor belt deliversproportioned quantities of dry ingredients to an elevatable batch mixerin the form of a paddle mixer which is tiltable, in an elevatedposition, to discharge the contents thereof.

U.S. Pat. Nos. 5624577 and 4538916 describe highly sophisticated,purpose built vehicles which operate as mobile batching and mixingapparatuses to deliver variable quantities of pre-mixed concrete asrequired.

Australian Patents Nos. 575263 and 590101 describe a mobile batching andmixing apparatus which is located at the rear end of a vehicle having atipping body. The apparatus, which is removably located in the tippingbody to release the vehicle for other uses, comprises containers forwater and cement powder and a plurality of metering devices for thevarious components of a concrete mix or the like. Bulk sand andaggregate is fed to respective metering devices under the influence ofgravity when the tipping body is raised.

Partial mixing of the dry ingredients is achieved by simultaneousmetering into the feed hopper of a mixing and discharge conveyor in theform of a screw auger located in a tubular housing. The dry ingredientsand water are introduced at one end of the auger housing and mixing anddischarge occurs as a continuous operation.

A particular disadvantage associated with the apparatus of AustralianPatents Nos. 575263 and 590101 is that the hopper of the mixing anddischarge conveyor must be centrally located below the outlets of thegravity fed metering devices. Accordingly the pivotally mounted innerend of the screw auger is lowered close to the ground surface as thevehicle body tips to feed the metering apparatus.

In order to compensate for this effective lowering of the dischargeconveyor and also to provide effective mixing during the continuousmixing and discharge operation, the screw auger is of extended lengthwhich extends well above the upper portion of the vehicle body when theauger is in an upright travelling position.

A further disadvantage of this apparatus is that the drive motor for theauger screw is necessarily located at the outer or free end of the augerto avoid contact with the ground surface and consequent damage when thevehicle body is elevated to the required tipping position. The placementof the drive motor at free end of the auger shaft in turn necessitates adischarge opening in the auger body adjacent the free end thereof on anunder surface.

Possibly the most serious disadvantage of all of the prior art apparatusreferred to above is that none are capable of movement and/or operationin regions of restricted access to areas such as vehicular carparks,basement areas of houses or other buildings, mine tunnels and the likebecause of limitations on headroom, width, axle load, turning circleetc.

Another disadvantage associated with all of the prior art apparatusreferred to above is that each represents a substantial capitalinvestment with high operational overheads due to the physical size andcomplexity of the apparatus.

SUMMARY OF THE INVENTION

Accordingly, it is an aim of the present invention to overcome orameliorate at least some of the disadvantages of mobile apparatus formixing and dispensing concrete or the like.

According to one aspect of the invention there is provided:

a mobile apparatus for mixing and dispensing of ingredients of amixture, said apparatus comprising;

mixing means for mixing predetermined quantities of said ingredients ofsaid mixture;

dispensing means for selectively dispensing said mixture, said mixingmeans and said dispensing means being located in a hollow body with aninlet opening adjacent said mixing means and an outlet opening adjacentan end of said dispensing means;

drive means operatively coupled with said mixing and said dispensingmeans;

mounting means for said mixing and said dispensing means, said mountingmeans comprising a track member, a carriage member slidably mounted onsaid track member and pivot means for pivotal attachment of said hollowbody to said carriage means.

According to another aspect of the invention there is provided amixing/dispensing apparatus for mixing ingredients of a mixture anddispensing of said mixture, said apparatus comprising:

a tapered helical ribbon blade supported on a rotatable shaft in afrusto-conical housing for relative rotation between said shaft and saidhousing, said housing having an inlet port and an outlet port.

According to yet a further aspect of the invention there is provided:

a mobile apparatus for mixing and dispensing mixtures of ingredientssaid apparatus comprising:

one or more container means for containing ingredients of a mixture;

metering means associated with said one or more container means, and

a tapered ribbon-blade mixer located within a frusto conical hollow bodyhaving an inlet opening and an outlet opening,

drive means to rotate said ribbon-blade mixer and/or said hollow body,and

mounting means for mounting said hollow body for slidable movement ofsaid body intermediate opposite sides of a transport vehicle.

Suitably said container means, metering means and conveyor means may bemounted on a transport vehicle such as a truck or lorry.

Suitably at least one of said container means comprises a hopper forparticulate material.

If required the hopper may include a sloping floor portion.

The hopper floor portion may slope upwardly from a normally forwardportion to a normally rear portion. Alternatively or additionally thehopper floor portion may slope transversely.

Suitably, the metering means may include a cover extending over thelength of the conveyor means. The cover may be raised or lowered tometer quantities of ingredients to the conveyor means via the gapbetween the cover and the sloping portion of the hopper floor. Suitably,said cover may include an extension of perforated material which ispivotally hinged to said cover to prevent settling of said ingredientmetered to said conveyor means.

Preferably the raising and lowering of the cover is controlled byhydraulic and/or pneumatic means.

Suitably the cover permits access to the conveyor means for maintenanceor cleaning purposes without the need to unload said ingredients.

The metering means associated with said container for a liquidingredient may comprise any suitable means for delivering apredetermined quantity of said liquid.

Suitably said liquid metering means comprises a liquid storage vesselwith a dump valve means.

The container means may include a container for a liquid ingredient of amixture.

Preferably where accurate metering of liquid ingredient is required saidliquid metering means may include a volumetrically controlled pump.

Suitably, the metering means associated with a hopper for particulatematerial comprises a conveyor means.

Preferably the conveyor means comprises a screw auger however conveyorbelt, chain scraper or other means may be used.

The mixing means may comprise paddles, blades, fingers or like membersassociated with a rotatable shaft.

Suitably the dispensing means comprises a screw auger.

Alternatively, said mixing means and dispensing means may be combined inthe form of a screw auger having continuous or discontinuous flights.

Preferably said mixing means and said dispensing means are coaxial forselective operation by said common drive means.

Preferably drive means in the form of an electric or hydraulic motor ordrive shaft from power take-off means may be used to rotate the mixingmeans and dispensing means or said ribbon blade mixer within the hollowbody or revolve the hollow body about a stationary mixing means anddispensing means or about said ribbon-blade mixer.

Suitably said drive means is located adjacent said inlet opening of saidhollow body and may comprise separate or common drive shafts.

Preferably the hollow body comprises an upper rigid section and a lowerresilient section.

Preferably said inlet opening is coverable and is located in an upperportion of said hollow body in the region of the mixing means to receiveingredients from said metering means.

If required said inlet opening may extend substantially along the upperportion of said hollow body.

Suitably, if required said hollow body may include a detachable ortelescopic chute extension, with or without a detachable dispensingauger locatable therein.

Suitably the tapering ribbon-blade mixer extends the length of thehollow body.

Preferably the tapering ribbon-blade mixer is located within the hollowbody so that there is a minimum clearance between the flights of saidribbon-blade mixer and the lower resilient section of the hollow body.To prevent excessive wear, flights of said ribbon blade mixer may belined or tipped with neoprene, polyurethane or other materialpermanently affixed by adhesive, mechanical or other suitable means.

Preferably, said mounting means comprises a track member, a carriagemeans slidably mounted on said track member and pivot means for pivotalattachment of said hollow body to said carriage means.

Suitably said hollow body is pivotally attached to said pivot meansabout an upright and/or transverse pivotal axis.

Suitably the position and inclination of said hollow body between anelevated and a declined position may be controlled by fluid ram,mechanical or other means.

Preferably said track member is adapted for mounting transversely at therear end of said transport vehicle.

If required said track member may extend longitudinally at one side ofsaid transport vehicle.

Retractable and extendable movement of said hollow body may be achievedby further mounting said pivot means to a telescopic extension membersuch as a scissors link device or other suitable arrangement.

In another version of the invention, the hollow body may be pivotallysupported by a telescopic boom. The telescopic boom may comprise ahorizontal hydraulically or pneumatically operated telescopic member anda vertical member which may be pivotally mounted adjacent either cornerof the rear of a delivery vehicle or mounted on a slidable mountingmeans which traverses the width of the rear or the lengths of the sidesof a delivery vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more fully understood and put intopractical effect, reference will now be made to a preferred embodimentillustrated in the accompanying drawings in which:

FIG. 1 shows a side elevational view of a mobile concrete mixer anddispenser according to the invention;

FIG. 2 shows a rear elevational view of the apparatus of FIG. 1

FIG. 3 is a partial rear perspective view of the apparatus of FIGS. 1and 2;

FIG. 4 shows a rear elevation of an alternative form of metering meansfor ingredients of a mixture.

FIGS. 5a, 5b and 5c respectively show a side elevation, top plan and endelevation of a further combined mixing and dispensing apparatusaccording to the invention;

FIG. 6 shows a side elevation of the tapered ribbon-blade mixer of theapparatus of FIGS. 5a, 5b and 5c; and

FIG. 7 is a partial side elevational view of the mixer/dispenser ofFIGS. 5a, 5b and 5c showing a mounting arrangement.

DETAILED DESCRIPTION OF THE DRAWINGS

In FIGS. 1 and 2 the apparatus 1 is mounted on the chassis 2 of atransport vehicle 3. As illustrated, the transport vehicle 3 is a 6.5ton GVM capacity vehicle although for the purposes of the followingdescription, it should be understood that the apparatus may be scaleddown to suit a smaller vehicle of say 1 ton or it may be scaled up tosuit vehicles of greater carrying capacity including articulatedvehicles.

Generally speaking however, the advantages of the invention will begreatest in vehicles having a carrying capacity in the range from 1 to 6tons due to their more compact construction and reduced headroomrequirements.

Apparatus 1 comprises a centrally mounted hopper 4 with inwardly anddownwardly sloping side walls 5. Located in a channel shaped floorportion 6, which slopes upwardly from near the front of hopper 4 to therear thereof, is a screw auger 7.

An hydraulic or electric drive motor 8 is provided forwardly of asloping front hopper wall 9 and the rear end of the auger shaft isjournalled in a housing 10 having a discharge opening 11.

Extending on each side of the lower part of hopper 4 and below is awater tank 12. The base of water tank 12 rests upon and is connected tothe chassis rails 2 of vehicle 3.

A retractable canopy 13 is provided at the upper portion of hopper 4 anda platform region 4a is provided along each side of water tank 12.

Mounted at the rear end of apparatus 1 is a mixing and dispensing device14 for mixing and selectively dispensing a mixture of ingredients.

As shown in FIG. 3, device 14 comprises an open trough-like body 15having a generally U-shaped cross section. Body 15 is closed at one endby end wall 16 to which an electric or hydraulic drive motor 17 ismounted. At the opposite end of body 15, the omission of an end wallcreates an opening 18 for selective dispensing of a mixture.

Drive motor 17 powers a drive shaft 19 having mounted thereon a ribbonblade mixer 20 and a dispensing auger 21. For the sake of clarity theblade mixer 20 and dispensing auger 21 are shown as an assembly 22. Thefree end (not shown) of shaft 19 is journalled in a bearing (not shown)which is slidable along an upright axis on bracket 23.

As shown in FIG. 3, bagged ingredients 24 of a mixture may be supportedfor transportation on platforms 4a if required.

Body 15 is pivoted about an upright axis on a bracket 25, bracket 25 inturn being slidably mounted on rails 26 for transverse movement from oneside of apparatus 1 to the other.

The operation of the apparatus will now be described with reference to amobile concrete mixing apparatus.

A quantity of sand and aggregate, premixed in predetermined proportionsis loaded into hopper 4 and water tank 12 is filled via a filler opening(not shown). A quantity of bagged cement powder is loaded onto platforms4a and vehicle 3 is driven to a site for delivery of site-mixedconcrete.

By means of a control panel (not shown) adjacent the rear end of vehicle3, a predetermined quantity of sand aggregate mix is metered into body15 by a controlled number of revolutions of screw auger 7. Forconvenience and simplicity of operation, the control panel may include ametering control for auger 7 calibrated in units equivalent to portionsof a bag of cement powder eg. 1/4 bag, 1/20 bag etc.

A predetermined quantity of sand/aggregate mixture requiring, say, onebag of cement for a required concrete strength of say, 20 Mpa, ismetered into mixer 20 and drive motor 17 is actuated for a mixing cyclewhile the cement powder is added. Suitably, the dry ingredients aremixed for a predetermined time by means of a timing device associatedwith the control panel.

When the "dry" mixing cycle is complete, the mixer controller apparatus(not shown) actuates a dump valve (not shown) in a cistern-like waterholding tank (not shown) which had previously been filled to apredetermined level from water tank 12 by pump (not shown).

For the configuration of mixer/dispenser assembly shown, the assemblymay be operated in a counter clockwise direction during a mixing cycleof predetermined duration. During the mixing cycle the curved sweep ofthe ribbon blades confines the concrete mix towards the mixing region ofbody 15 and the innermost flight of auger 21 also assists in thisregard.

After a mixing cycle of predetermined duration the mixer controllerreverses the direction of rotation of the assembly 22 causing theconcrete mix to be dispensed via opening 18 in body 15. By mounting body15 for pivotal movement about an upright axis on slidable bracket 25,body 15 is able to operate as a dispensing chute swingable through 180°and able to dispense the mix on either side of vehicle 3 at a distanceequivalent to the length of body 15.

The apparatus described above is particularly suited to mixing anddispensing small quantities of concrete, either for small single batchusage applications or in situation where dispensing of small quantitiesof concrete over a prolonged period of time are concerned. Moreover, thecompact dimensions of the apparatus are such that it is able to enterregions of reduced headroom otherwise denied to conventional mobileconcrete mixers and/or dispensers.

It will be readily apparent to a skilled addressee that manymodifications and variations may be made to the invention withoutdeparting from the spirit and scope thereof.

For example, the hopper 4 may be divided into two or more compartments,each with a respective material metering means such as a screw auger,conveyor belt, chain scraper or the like.

The apparatus may include a storage chamber for cement powder includingaeration means and a metering device such as a paddle wheel dispenser orthe like with an outlet chute in the region of the mixing portion ofassembly 22.

Similarly, the apparatus may include a water metering means such as avolumetrically controlled pump whereby each of the constituent meteringmeans is controlled by a central control means to produce concrete of aspecified strength and slump.

In other embodiments, the mixing and dispensing body 15 may be mountedfor selective inclination about a transverse axis to permit thedischarge end to be raised or lowered as required. Body 15 may alsoinclude a detachable or telescopic chute extension, with or without adetachable dispensing auger locatable therein for connection to the freeend of assembly 22 for rotation therewith.

The mixing and dispensing assembly 22 may simply comprise a reversiblescrew auger with continuous or discontinuous flights at the mixing end.Alternatively, the mixing portion and the dispensing portion may bemounted for relative coaxial rotation with a clutch mechanism orplanetary gear assembly for selective individual rotation, co-rotationor counter rotation during respective mixing and/or dispensing cycles.In such an arrangement, the body portion 15 may be positioned with itsrear end located below the constituent feed outlets to achieve acontinuous mixing and dispensing action if required as distinct from abatch process.

As shown in FIG. 4 an alternative form of metering means may comprise arigid cover 28 extending over the length of the screw auger 7. The cover28 has wing-like extensions 28a of steel mesh which are pivotallyattached to cover 28 by pivotal connections 28b and 28c.

The cover 28 is attached at either end to vertically mounted fluidpowered rams 30 and may be raised or lowered by independently orsynchronously operating the fluid powered rams.

The resulting gap 31 between the cover 28 in the raised position asshown in phantom and the hopper floor 33 permits a controlled flow ofparticulate materials to the screw auger 7. The quantity of ingredientscan be metered by controlling the width of the gap 31 during operationof auger 7. The lowermost region of the screw auger 7 is in closeproximity to the hopper floor 33 which is fabricated of resilientflexible sheet material such as natural or synthetic rubber orelastomeric materials such as semi-rigid polyurethane. By restrictingthe region of contact between the auger and the hopper floor and also byvirtue of the resilient floor material, jamming and/or damage to theauger by particles of aggregate is avoided.

In use, after a predetermined quantity of particulate material ismetered into the screw auger 7 via gap 31 and the cover 28 returned toits closed position, the screw auger conveys the entire quantity ofparticulate material to the mixer dispenser leaving the region betweenthe cover 28 and the hopper floor 33 free of particulate material.Accordingly when the vehicle travels from site to site, compaction ofthe particulate material in the region of the screw auger 7 isprevented. Such compaction can lead to drive motor overload (and damage)or otherwise a substantially stronger motor would be required to drivethe screw auger.

A particular advantage of cover 28 is that in the event that auger 7requires maintenance, the auger screw can be removed from the base ofthe hopper without first having to manually empty the contents of thehopper.

The steel mesh wing-like extensions 28a serve in use to prevent unevenflow of particulate material from the hopper 4 to the auger 7. As cover28 is raised to permit flow of particulate material to the auger 7 viagap 31, the pivoted wing-like extensions 28a are lifted thus disturbingthe mass of particulate material thereabove to prevent localisedbridging or compaction within the hopper 4.

Moreover, the auger cover 28 not only serves to prevent bridging of theparticulate mixture in the hopper, it may be used to control the flow ofmaterial to the auger. Selective use of the cover 28 prevents the augerfrom flooding thereby permitting the use of a larger auger diameter,lower rotational speed, less powerful drive system and a less robustauger construction.

FIGS. 5a, 5b and 5c respectively show a side elevation, top elevationand end elevation of an alternative aspect of the invention whichcomprises a combined mixing and dispensing apparatus including a bodyportion 34 having an upper portion 35 fabricated from rigid metalsheeting such as stainless steel and a lower portion 36 fabricated fromflexible or resilient sheet material such as natural or synthetic rubberor elastomeric materials such as semi-rigid polyurethane.

There is provided in the upper portion a coverable opening 37 to receiveingredients for mixing.

Located within and extending the length of the body as indicated by thebroken lines 38a in all views is the outline of a tapered ribbon-blademixer 38 shown partially in FIG. 5b. The tapered ribbon-blade mixer 38is located within the body so that there is a minimum clearance betweenthe flights of the mixer blades and the lower flexible portion of thebody 36.

Also shown attached to the body is a hydraulic motor 39 used to drivethe ribbon-blade mixer. On either side of the hydraulic motor arebrackets 40 which are attached to the body for pivotal mountingpurposes.

Referring to FIG. 6 it can be seen that the tapered ribbon-blade mixer38 is comprised of a central shaft 38b to which are attached radialsupport members 38c to which support the ribbon-blade member 38d. Theribbon blade mixing/dispensing apparatus to one aspect of the inventiondiffers from conventional ribbon blade mixers in that it is generallyfrusto-conical in shape with the discharge and located at its narrowestdiameter.

Ribbon blade mixers generally sweep a cylindrical volume in atrough-like chamber having a semi-circular bottom portion. Althougheffective as mixers conventional ribbon mixers are poor materialsconveyors and thus are not used for this purpose. A screw auger havingsolid flights is effective as a conveyor but is a poor mixer as it tendsto convey a mass of material without subjecting it to any shear forces.

With this aspect of the invention, an efficient mixing function isachieved towards the larger end of the body with limited conveyingwhereas a more efficient conveying function is achieved towards thesmaller open end of the body. This is due to the smaller blade area whencompared to the cross sectional area of the body towards the larger endwhich is better suited for the mixing function. Conversely, theconveying function is more efficient at the smaller open end of the bodydue to the relatively larger blade area when compared to the internalcross sectional area.

As the helical blade of the tapered ribbon blade mixer has a relativelysmall surface area compared with a screw auger, its power requirementsare considerably less. To avoid undue wear on the relatively thin bladeflight, the flight is manufactured from hardened steel or includes wearresistant wear faces. Conveniently, the blade includes a wear resistantpolymeric sheath such as an extruded polyurethane or synthetic rubbermaterial which may be attached to the flight by an adhesive or the like.

The largely self cleaning nature of the mixer/dispenser with acombination of a rigid upper portion and a flexible lower portion allowsany small amounts of residual mixture to be left in the body without thenecessity of washing out the body between mixes. A thin film of anyresidue which may have hardened against the flexible lower portion isbroken up by new particulate matter in a successive mixing.

Referring to FIG. 7 it can be seen that the pivotal mounting means 43for the apparatus of FIG. 5a, 5b and 5c comprises a mounting member 44to which a fluid powered ram 45 is attached.

Attached to the body 46 are brackets 47 which are pivotally attachedalong a transverse axis to the mounting member 44 by a high tensilesteel bolt 49a and locknut 49b. The fluid powered ram 45 is pivotallyattached to the mounting member 44 at pivot points 48 by a high tensilesteel bolt 48a and locknut 48b and to the body 46 by pin 49.

There is also attached to body 46 a hydraulic motor 50 which is used todrive the tapered ribbon-blade mixer 38.

Attached to the mounting member 44 is an upright bearing housing 44awhich permits the body 46 to pivot about an upright axis for positioningpurposes when dispensing a mixture. To permit transverse movement of thebody 46 from one side to the other of a transport vehicle, the housing44a is mounted to a carriage member which is slidably mounted on tracks(not shown).

In use, the extension of the fluid powered ram permits selectiveelevation and lowering of the body. Mixing of ingredients may be carriedout in the elevated position and then dispensed as the body is lowered.

It will be apparent to a skilled addressee that, with appropriatemodifications, the apparatus may be mounted on retractable legs, a skip,trailer or the like to free a transport vehicle for other purposes. Foroperation independent of a transport vehicle, the apparatus may includean integral power plant or a portable power plant for electric and/orhydraulic power. Similarly, the apparatus may be adapted for use with avariety of mixtures such as animal feedstuffs, seeded and fertilised topdressing mixtures for agricultural use, road base mixtures, bituminousor asphaltic road surfacing materials, explosives compositions such asammonium nitrate/fuel oil mixtures and the like.

In other embodiments, the metering and/or mixing and/or dispensingaugers may be associated with flexible walls of rubber or plasticsmaterials to avoid jamming in the event that an aggregate particlelodges between the edge of the auger flight and the auger wall. Thedispensing auger may include a tubular body at the dispensing end tofacilitate pressurised dispensing or operation with the dispensing endof the auger in an elevated position.

In a very simple, inexpensive embodiment of the apparatus, it maycomprise a rail assembly mounted transversely at the rear of a vehicletray or tipper body with the mixing/dispensing apparatus pivotallyattached to a carriage slidably mounted on the rail assembly. Premixedsand and aggregate may be stored on the tray or in the tipper body inbulk or in containers together with containers for water and cementpowder in bags or in bulk. The ingredients of the mixture may be meteredinto a feed hopper associated with the mixing apparatus by suitablemetering means or simply by a shovel or the like.

In yet another simple embodiment of the invention, the mixing/dispensingapparatus may be mounted for slidable and pivotal movement transverselyat the rear of a conventional concrete agitator bowl vehicle. In thisarrangement, the agitator bowl may contain a dry mix of sand andaggregate or even a dry mix of sand, aggregate and cement powder. Onsite, cement powder and/or water is added to the mixing/dispensingapparatus for selective batch or continuous production of quantities ofconcrete.

When mounted to a mobile apparatus the mounting means may comprise atelescopic linkage between the carriage and the mixer/dispenser toprovide an even greater flexibility of use. Preferably however thetransverse rail assembly which supports the slidable carriage may bemounted on extendable beam members slidably extending along oppositesides of the vehicle chassis or body.

To illustrate the flexibility and adaptability of the apparatus, theassembly of FIGS. 1-3 may be adapted to facilitate removal of housing 10by means of a quick coupling device and replacement thereof with acement powder container. The cement powder container includes a meteringdevice such as a paddle wheel dispenser operatively coupled to theelectrical and/or hydraulic controls for the apparatus for accuratemetering of cement powder with the sand/aggregate mix to the feed hopperof the mixing apparatus.

The apparatus according to the various aspects of the invention isreadily mountable on four or six wheel drive vehicles or a trackedvehicle for use in difficult site conditions and is particularlysuitable for operation in remote areas beyond the operational limits ofconventional ready mixed concrete delivery vehicles. With appropriatemodifications, the apparatus is considered to be applicable to civilemergency and military use for, say, rapid repair of damaged roadwaysand concrete runaways using rapid setting cement, sand bag filling andthe like. With this apparatus, relatively small craters which couldotherwise render a roadway or runway unusable can be repaired and theroadway or runway restored to operational status within a very shortperiod of time.

A particular advantage of the present invention over similar prior artbatching and mixing apparatus is that it can be constructed simply andinexpensively yet with sufficient simple control mechanisms forconsistent concrete quality even with unskilled operators. Unlikeconventional agitator bowl concrete delivery vehicles which are "tied"to a "mother" batch plant and thus must return empty from each deliverytrip, the apparatus according to the present invention is able to refillwith sand/aggregate, cement powder and water at a variety of sourcesthereby improving operational efficiency.

I claim:
 1. A mobile apparatus for mixing and dispensing of ingredientsof a mixture, said apparatus comprising:a rotatable mixer for mixingpredetermined quantities of said ingredients of said mixture; arotatable dispenser for selectively dispensing said mixture, said mixerand said dispenser being located in a hollow body with an inlet openingadjacent said mixer and an outlet opening adjacent an end of saiddispenser; a drive motor operatively coupled with said mixer and saiddispenser; and a mounting member for supporting said mixer and saiddispenser, said mounting member comprising a track member, a carriagemember slidably mounted on said track member and a pivot for pivotalattachment of said hollow body to said carriage member.
 2. A mobileapparatus as claimed in claim 1 having one or more containers forcontaining ingredients of a mixture andan ingredient metering deviceconnected with the interior of at least one of said one or morecontainers.
 3. A mobile apparatus as claimed in claim 2 wherein said oneor more containers further includes a hopper for particulate material.4. A mobile apparatus as claimed in claim 3 wherein said one or morecontainers further includes a liquid container for a liquid ingredientof a mixture.
 5. A mobile apparatus as claimed in claim 2 wherein saidmetering device comprises a screw auger.
 6. A mobile apparatus asclaimed in claim 5 wherein said metering device comprises a covermovable between an open and a closed position to permit, in use, aselective flow of particulate material from said one or more containersto said screw auger.
 7. A mobile apparatus as claimed in claim 1 whereinsaid mixer and said dispenser rotate about a common axis.
 8. A mobileapparatus as claimed in claim 1 wherein said track member is mountedtransversely of a longitudinal axis of a transport vehicle.
 9. A mobileapparatus as claimed in claim 8 wherein said track member also extendsaround one or both sides of a transport vehicle parallel to saidlongitudinal axis.
 10. A mobile apparatus as claimed in claim 1 whereinsaid mounting member is extendably mounted to said transport vehicle.11. A mobile apparatus as claimed in claim 1 wherein said mixer and saiddispenser comprise a tapered helical ribbon blade supported on arotatable shaft in a frusto-conical housing for relative rotationbetween said shaft and said housing, said housing having an inlet portand an outlet port.
 12. A mobile apparatus as claimed in claim 11wherein said inlet port is adjacent a larger diameter end of saidhousing and said outlet port is adjacent a smaller diameter end of saidhousing.
 13. A mobile apparatus as claimed in claim 11 wherein saidhousing comprises a lower resilient wall portion.
 14. A mobile apparatusas claimed in claim 11 wherein said ribbon blade comprises a wearresistant material.
 15. A mobile apparatus as claimed in claim 14wherein said ribbon blade comprises a removable sheath of flexible wearresistant polymeric material.
 16. A mobile apparatus as claimed in claim11 wherein a drive motor is associated with said shaft adjacent saidinlet port.